Issa glared down from the dais. Although a swearing-in ritual is not usually a time for badgering the witness, he couldn’t help himself. “You certainly have some explaining to do,” he said.

Rep. Darrell Issa, R-Calif., the chairman of the House Oversight Committee, questions Internal Revenue Service Commissioner John Koskinen as lawmakers continue their probe of whether tea party groups were improperly targeted for increased scrutiny by the IRS. (J. Scott Applewhite/AP)

The bullying was vintage Issa, in his last year as chairman of the House Committee on Oversight and Government Reform. He followed the stunt with frequent interruptions of colleagues to inject his thoughts, parliamentary arguments with Democrats and takings of personal umbrage. He thought it helpful to mention his own “experience as a CEO.”

Issa has a genuine scandal in the IRS’s claim that many of former employee Lois Lerner’s e-mails were lost because her hard drive crashed. But instead of keeping the focus on the agency, he has responded as he has repeatedly — by drawing attention to himself.

You might say Issa has subpoena envy.

The flamboyant California Republican has in recent weeks clashed with three other House committees over the reach of their competing investigations, most recently with Ways and Means Committee Chairman Dave Camp (R-Mich.).

When word came last week that the IRS had lost the e-mails, Camp’s panel said it would hold a hearing with Koskinen (voluntarily) appearing on Tuesday, June 24. Ten minutes after that announcement, Issa proclaimed that he was issuing a subpoena to Koskinen to force his appearance the night before Camp’s hearing – at 7 p.m. on Monday, June 23. The commissioner then discovered another opening in his schedule – and Camp leapfrogged Issa, moving his hearing up to Friday, June 20.

This left Issa in the unenviable position of holding a rare nighttime hearing Monday — and all the urgency it conveys — to question a witness who already had been thoroughly and fiercely cross-examined three days earlier. The halls of the Rayburn Building were quiet, and only half of Issa’s committee members were in the room as the hearing got underway 15 minutes late.

As Koskinen waited for Issa and his colleagues to arrive, he strolled over to the press table and spoke about how Issa would try to top Camp’s hearing. “The roughness on Friday got enough coverage that I’m sure they’re all trying to figure out how they can be tougher,” the commissioner said.

He was right about that. Issa wasn’t first, but he was the most furious. He directed all manner of invective at Koskinen: “Cover-up . . . caught red-handed . . . false or misleading . . . sick and tired of your game-playing . . . questioning what your word is worth . . . we have a problem with you and you have a problem with maintaining your credibility.”

“This event in history, like Watergate, like Teapot Dome and like many other historic events,” Issa said, “will be studied by future generations without the benefit of many of the thoughts of Lois Lerner and others at the IRS.”

This followed Issa’s accusations in recent days that the White House was lying, that there was “nefarious conduct that went much higher than Lois Lerner,” and that Lerner “acted on” President Obama’s wishes. On Monday morning, Issa told Fox News Channel that “the Justice Department, the IRS and the White House are interested in her succeeding in hiding what she’s hiding.”

In the past, similar allegations of high-level wrongdoing have undermined Issa’s investigations when he failed to back them up. His inability to deliver the goods in the Benghazi investigation led House Republicans to hand the matter to a select committee under Rep. Trey Gowdy (R-S.C.). Issa at first refused to yield in his Benghazi probe, and he issued a subpoena for Secretary of State John Kerry to testify before his panel; Issa eventually abandoned that request after it became clear that Issa’s subpoena would deny the Gowdy panel its chance at Kerry.

Likewise, Issa drew the ire of Armed Services Committee Chairman Buck McKeon (R-Calif.), who disputed the credibility of a retired general Issa had called as a witness. McKeon said the general did not have “reliable insight” on the matters he testified about. This followed an earlier territorial dispute Issa had with the Energy and Commerce Committee over the Solyndra investigations.

The IRS’s belated discovery and admission to Congress that it lost a chunk of Lerner’s e-mails is inexcusable — just as inexcusable as similar e-mail gaps that were discovered during investigations of the Clinton administration’s fundraising practices and the George W. Bush administration’s firing of U.S. attorneys and memos on torture. Issa’s anger about the e-mails would be more compelling if he had shown more interest in these previous episodes, or in fixing the woeful state of the federal government’s electronic records — and less in the angle of his witness’s raised right arm.

Twitter: @Milbank

Dana Milbank writes about political theater in the nation’s capital. He joined the Post as a political reporter in 2000.